Despite a growing interest in developing non-invasive methods to identify rare cancer cells or cancer cell DNA in blood, current techniques remain complicated and often prohibitively expensive. Now, UCLA researchers have pioneered a more effective approach to these "liquid biopsies" that has the potential to offer a streamlined and low-cost solution for people with the disease.

Dr. Dino Di Carlo

The technology works by creating millimeter-scale whirlpools to draw in and concentrate circulating tumor cells, known as CTCs, based on their size. CTCs often appear as large abnormal cells in the circulation of cancer patients and can be used by scientists as cellular markers of the disease. Analysis of these cells promises to provide critical information about which treatments are best suited and most effective for a patient, and whether those receiving a therapy may relapse.

"CTCs are extremely rare, so isolating them is a problem similar to finding a needle in a haystack," said Dr. Dino Di Carlo, director of the Jonsson Comprehensive Cancer Center Nanotechnology Program and professor of bioengineering at the UCLA Henry Samueli School of Engineering. "Our filterless system avoids issues of previous technologies that clog and break cells apart, and we found this approach was more effective than technologies currently available at isolating cells from breast and lung cancer patients."

In a two-year study, Di Carlo's team isolated cells and detected specific proteins on these cells from 50 patients. In a subset of these patients they then compared the number of CTCs discovered by the FDA-approved gold standard instrument and found significantly higher numbers of cells per patient, with over 80 percent of patients having CTC levels above age-matched healthy individuals compared to only 20 percent with the currently approved instrument.

In a previous study published in 2014, the researchers found that the micro-whirlpools, or vortices, entrapped cancer cells with epithelial characteristics in a small number of patients (epithelial cells help to protect or enclose organs within the body). The new findings showed that nearly half of the CTCs isolated with this new Vortex HT system developed by UCLA researchers didn't have epithelial-like markers and that the number of CTCs isolated in the same time was almost doubled compared to the previous iteration of the technology.

Di Carlo said he hopes the new system will enable clinicians to better understand how to administer and monitor treatments and that in the long-term such an approach could potentially be used to detect cancer much earlier with a simple blood test.